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Theses/Dissertations

University of Massachusetts Amherst

Bioaccessibility

Articles 1 - 4 of 4

Full-Text Articles in Life Sciences

The Efficacy Of Nanoemulsion-Based Delivery Systems To Improve Vitamin D3 Bioaccessibility And Bioavailability, Alagu Selvi Kadappan Jul 2019

The Efficacy Of Nanoemulsion-Based Delivery Systems To Improve Vitamin D3 Bioaccessibility And Bioavailability, Alagu Selvi Kadappan

Masters Theses

Vitamin D deficiency is an epidemic issue in all age groups in Western countries and that affects both skeletal and non-skeletal functions. Even with the wide application of food fortification, vitamin D deficiency tends to increase continuously. Being hydrophobic in nature, vitamin D has poor solubility; thereby it negatively affects its absorption and bioavailability when compared to other hydrophilic dietary compounds. The need to develop a novel strategy is of greater importance to enhance its bioavailability and thereby improving vitamin D level in the body.

In this study, lipid-based delivery of oil-in-water nanoemulsion (diameter < 200nm) was utilized to improve the bioaccessibility and oral bioavailability of vitamin D3. First, we examined the in ...


Fabrication, Characterization And Biological Fate Of Phytochemical Delivery System, Jingjing Chen Nov 2015

Fabrication, Characterization And Biological Fate Of Phytochemical Delivery System, Jingjing Chen

Doctoral Dissertations

Polymethoxyflvones (PMFs) are a group compounds with promising cancer preventing activities and many other health benefits. There's a growing interest in fabricating delivery systems for PMFs as well as other phytochemicals due to their low water solubility. Firstly, we use nanoemulsion delivery system to encapsulate β-carotene. Sonication assisted method was developed to dissolve β-carotene to ensure minimum degradation. Powdered nanoemulsion was obtained after spray dry and freeze dry. Sample obtained after freeze dry showed better physiochemical characteristics. Then we use protein nanoparticle delivery system to encapsulate PMFS. The nanoparticle delivery system was fabricated by mixing the aqueous phase ...


Rationalizing Nanoemulsion Formation For Encapsulation, Protection And Delivery Of Bioactive Food Components, Ying Yang Mar 2015

Rationalizing Nanoemulsion Formation For Encapsulation, Protection And Delivery Of Bioactive Food Components, Ying Yang

Doctoral Dissertations

The objective of this thesis was to design and develop novel food-grade nanoemulsion-based delivery systems for the encapsulation, protection and delivery of lipophilic bioactive food components. These delivery systems could be widely applied in aqueous-based fortified food products, such as beverages, salad dressing and yogurt etc.

Both the low- and high-energy methods could be used for fabricating nanoemulsions (r < 100 nm). The microfluidization method could form nanoemulsions at low surfactant-to-oil ratios (SOR < 0.1), but it required the use of high-energy inputs and expensive equipment. On the other hand, the spontaneous emulsification method could also form ultrafine emulsions and moreover it was simple and inexpensive, but it required much higher surfactant-to-oil ratios (SOR > 0.5) for forming nanoemulsions.

Q-Naturale® is a natural food-grade surfactant, which is got from the bark of the Quillaja saponaria Molina tree. By using high pressure homogenization (microfluidization), Q-Naturale® could form relatively small droplets (d < 200 nm) at low surfactant-to-oil ratios (SOR < 0.1), but the droplets were not as small as those produced using Tween 80 under similar conditions (d < 150 nm). The emulsions formed by using Q-Naturale® as the emulsifier were ...


Influence Of Physical States (Crystalized Versus Solubilized) Of Bioactive Components And Oil Composition On Bioaccessibility And Bioavailability, Ziyuan Xia Aug 2014

Influence Of Physical States (Crystalized Versus Solubilized) Of Bioactive Components And Oil Composition On Bioaccessibility And Bioavailability, Ziyuan Xia

Masters Theses

Three systems were compared in the first case study: (1). pre-dissolved β-carotene nanoemulsion (d< 200nm); (2). corn oil emulsion (d< 200nm) with β-carotene crystals being added before digestion; (3). phosphate buffer saline with β-carotene being added before digestion. Oil-in-water nanoemulsions were formed by high-pressure homogenization using Tween 20 as emulsifier and corn oil as carrier oil and then they were subjected to a simulated mouth, stomach and small intestine digestion. The rate and extent of free fatty acid production in small intestine decreased in the order (2)>(1)>(3); whereas the β-carotene bioaccessibility decreased in the order (1)>>(2)>(3). In system (3), even without any fat content, there is still noticeable consumption of NaOH, which is due to the ester bonds existing in the non-ionic surfactant (Tween 20). In the second case study, we developed two comparing groups by differentiating their oil concentration (20%, 4% respectively). The bioaccessibility of the high fat group is only half of the low fat group due to the insufficient digestion of fat in the former ...